Some things to check to see if your barn is in good condition is any visible damage. Some indication of damage could be that caused by horses or livestock or any fire hazards that could be located in or outside of the building. Another important factor in using the barn is the electricity. The lights and receptacles should be GFCI protected. Also check for any extension cords, which can be an indication the barn isn't updated or could overload the system and can also pose a tripping hazard.
Whatever the reason you use the barn on your property, these are some good tips to use when checking the condition of the barn.